<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Crypt
 * @subpackage Math
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Bcmath.php 16971 2009-07-22 18:05:45Z mikaelkael $
 */

/**
 * @see Zend_Crypt_Math_BigInteger_Interface
 */
require_once 'Zend/Crypt/Math/BigInteger/Interface.php';

/**
 * Support for arbitrary precision mathematics in PHP.
 *
 * Zend_Crypt_Math_BigInteger_Bcmath is a wrapper across the PHP BCMath
 * extension.
 *
 * @category   Zend
 * @package    Zend_Crypt
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Crypt_Math_BigInteger_Bcmath implements Zend_Crypt_Math_BigInteger_Interface
{

	/**
	 * Initialise a big integer into an extension specific type. This is not
	 * applicable to BCMath.
	 * @param string $operand
	 * @param int $base
	 * @return string
	 */
	public function init($operand, $base = 10)
	{
		return $operand;
	}

	/**
	 * Adds two arbitrary precision numbers
	 *
	 * @param string $left_operand
	 * @param string $right_operand
	 * @return string
	 */
	public function add($left_operand, $right_operand)
	{
		return bcadd($left_operand, $right_operand);
	}

	/**
	 * @param string $left_operand
	 * @param string $right_operand
	 * @return string
	 */
	public function subtract($left_operand, $right_operand)
	{
		return bcsub($left_operand, $right_operand);
	}

	/**
	 * Compare two big integers and returns result as an integer where 0 means
	 * both are identical, 1 that left_operand is larger, or -1 that
	 * right_operand is larger.
	 * @param string $left_operand
	 * @param string $right_operand
	 * @return int
	 */
	public function compare($left_operand, $right_operand)
	{
		return bccomp($left_operand, $right_operand);
	}

	/**
	 * Divide two big integers and return result or NULL if the denominator
	 * is zero.
	 * @param string $left_operand
	 * @param string $right_operand
	 * @return string|null
	 */
	public function divide($left_operand, $right_operand)
	{
		return bcdiv($left_operand, $right_operand);
	}

	/**
	 * @param string $left_operand
	 * @param string $right_operand
	 * @return string
	 */
	public function modulus($left_operand, $modulus)
	{
		return bcmod($left_operand, $modulus);
	}

	/**
	 * @param string $left_operand
	 * @param string $right_operand
	 * @return string
	 */
	public function multiply($left_operand, $right_operand)
	{
		return bcmul($left_operand, $right_operand);
	}

	/**
	 * @param string $left_operand
	 * @param string $right_operand
	 * @return string
	 */
	public function pow($left_operand, $right_operand)
	{
		return bcpow($left_operand, $right_operand);
	}

	/**
	 * @param string $left_operand
	 * @param string $right_operand
	 * @return string
	 */
	public function powmod($left_operand, $right_operand, $modulus)
	{
		return bcpowmod($left_operand, $right_operand, $modulus);
	}

	/**
	 * @param string $left_operand
	 * @param string $right_operand
	 * @return string
	 */
	public function sqrt($operand)
	{
		return bcsqrt($operand);
	}


	public function binaryToInteger($operand)
	{
		$result = '0';
		while (strlen($operand)) {
			$ord = ord(substr($operand, 0, 1));
			$result = bcadd(bcmul($result, 256), $ord);
			$operand = substr($operand, 1);
		}
		return $result;
	}


	public function integerToBinary($operand)
	{
		$cmp = bccomp($operand, 0);
		$return = '';
		if ($cmp == 0) {
			return (chr(0));
		}
		while (bccomp($operand, 0) > 0) {
			$return = chr(bcmod($operand, 256)) . $return;
			$operand = bcdiv($operand, 256);
		}
		if (ord($return[0]) > 127) {
			$return = chr(0) . $return;
		}
		return $return;
	}

	/**public function integerToBinary($operand)
	 {
	 $return = '';
	 while(bccomp($operand, '0')) {
	 $return .= chr(bcmod($operand, '256'));
	 $operand = bcdiv($operand, '256');
	 }
	 return $return;
	 }**/ // Prior version for referenced offset


	public function hexToDecimal($operand)
	{
		$return = '0';
		while(strlen($hex)) {
			$hex = hexdec(substr($operand, 0, 4));
			$dec = bcadd(bcmul($return, 65536), $hex);
			$operand = substr($operand, 4);
		}
		return $return;
	}

}